Transfer Case Max Torque

[Unforgiven]

Does anyone know the max hp/torque the stock A2 transfer case can handle? I ask because I want to add hydraulics in back & keep the winch up front, meaning I need to spend the $$ for a rear output PTO. For reasons I don't care to get into, I plan to use a telescopic hoist instead of a scissors hoist. Therefore, b/c of the volume of fluid needed the PTO pump is the better choice.

But, long term (5 years or so) I wouldn't mind doing a tranny/engine swap to something newer. Why? B/C I just bought the truck and it's in okay shape for the price. But it's obvious if I'm going to keep it there's going to have to be tranny work, synchros, clutch, etc. at some time in the future. So if I upgrade to a newer, more powerful engine/tranny combo what is the maximum torque the transfer case can handle?

Otherwise I'd have to get another TC & another PTO, which I would hope to not do b/c of the $$. Are stock A2 transfer cases easily adaptable to other trannys?

 

[Westech]

someplace around 300 and 2396.5 foot pounds really its rated for 300 but we all see them in big block high HP monster trucks.

 

[Unforgiven]

So monster trucks are running these transfer cases? If that's so there shouldn't be any problems with something like a Duramax/Cummins/Allison type swap. Thanks for the info. If they are used in the big show trucks then they must be pretty tough transfer cases.

Have you ever separated the tranny from the transfer case? Is it just a splined shaft between them with gaskets/seals? If so then a competent machine shop could easily fabricate a custom shaft for almost any type of swap.

Sorry for so many questions. Like I said I'm new to this truck. But I'm trying to plan "just in case" upgrades. So in your opinion, if I go with a rear output PTO I should be able to save it just incase there's a different tranny in 10 years?

 

[jblack6527]

The transfer case is already separated from the trans. They have a small driveshaft between them.

 

[Ridgerunner]

I ask because I want to add hydraulics in back & keep the winch up front.



I wouldn't mind doing a tranny/engine swap to something newer.

Don't forget, with your intended engine/tranny swap. The front winch PTO is driven off from the transmission. Swaping to a different tranny, might eliminate that PTO output for the winch. It's just a thought.....

 

[gimpyrobb]

Could always put a hydro motor on it though.

 

[Unforgiven]

Don't forget, with your intended engine/tranny swap. The front winch PTO is driven off from the transmission. Swaping to a different tranny, might eliminate that PTO output for the winch. It's just a thought.....

Poop!

Well it was an idea. I guess any future tranny swaps will just be $$$

 

[Unforgiven]

I looked into the Medium/Heavy Duty Allisons. Nearly all of them have provisions for PTO. Some even have dual PTO ability, with side-by-side PTO's or over/under PTO's. There are so many Allison models it's ridiculous.

So, to answer my own question, yes. I can go ahead & set the truck up with a stock dual-output PTO with winch up front & hydraulic pump on rear. The only thing with a future tranny swap would be to pick a model that has dual, side-by-side PTO, or a single PTO with dual output, just like the A2. I'm betting the A2 dual output PTO would not work at all, so a new PTO would be needed. But other than a new PTO for the new tranny the rest of any hydraulics I might add would not be wasted and the PTO drive shafts should only require minor modifications. I think it's great the A2 has a driveshaft between the tranny & transfer case. I've never seen that. And it's pretty long too. More than enough space to chop it a few inches for a longer tranny. That really makes a future tranny swap appealing.


Some of the larger Allisons for emergency vehicles have a manually selected granny gear that's even lower than the stock A2 1st gear. And they have two overdrive gearings. In essence, making a 3 way gear-splitter on a stock tranny if you look at the numbers. I think these Allisons are too big though. They are very long & heavy. The medium duty like the 3500s are more applicable to the size of the truck. For those who are curious, here's a link for the Allison Emergency Vehicle trannys.

Emergency Vehicle Series
http://www.allisontransmission.com/documents/product/specs_EVS.pdf

Rugged Duty Series
http://www.allisontransmission.com/documents/product/specs_RDS.pdf

Truck/RV Series
http://www.allisontransmission.com/documents/product/specs_TRV.pdf

Miscellaneous models
Transmissions << Atlantic Detroit Diesel - Allison

Why Allison? No reason. Just wanted to get an idea of what was available. But if I ever do a tranny swap I want an automatic. That way if I do something stupid like break my leg hiking, the wife can drive me to the hospital. And, since I live in the city it would be more convenient. I like stick. But like I said earlier, this truck I just bought needs some TLC. The tranny is not in the greatest shape. So if I have to do tranny work in a few years I want automatic overdrive.

 

[ken]

Couln't you get a transfercase from a fuel truck, Dump truck, Or pole setter truck with a PTO on the transfercase? Then you could keep the two seperate. The winch on the tranny. And the pump on the transfercase. Or, get a universal hyd belt drive pump from northern equip. Then just mount it above the alternator. A few custom brackets would be much cheeper. and easier than swapping heavy iron.

 

[Unforgiven]

Couln't you get a transfercase from a fuel truck, Dump truck, Or pole setter truck with a PTO on the transfercase? Then you could keep the two seperate. The winch on the tranny. And the pump on the transfercase. Or, get a universal hyd belt drive pump from northern equip. Then just mount it above the alternator. A few custom brackets would be much cheeper. and easier than swapping heavy iron.

That's a neat idea. I never thought about a transfer case swap. It would have to be a disconnected TC that would fit the input driveline on the A2. As far as keeping the winch on the tranny, I was planning to convert to a different tranny in a few years. The engine mounted pumps don't give enough volume for a telescopic dump hoist. Well, they do but it would take several minutes to raise.

 

[Westech]

I just sold a t case from a dump in June.. there out there for sure. Just hard to find.

 

[gringeltaube]

............................................. I think it's great the A2 has a driveshaft between the tranny & transfer case. I've never seen that. And it's pretty long too. More than enough space to chop it a few inches for a longer tranny. That really makes a future tranny swap appealing.
..................................................

Tranny to TC DS pretty long??? Chop it a few inches ???? I'm not so sure on that...
Might be better to move the TC back a few inches.

G.

 

[73m819]

one more thought on this that i have not seen mentioned here, the front drive shaft is real close to the trans, you start changing trans and ptos, you need to check the driveline clearences BEFORE you do anything, other wise you might end up with a pto in the middle of the driveshaft

 

[Unforgiven]

Tranny to TC DS pretty long??? Chop it a few inches ???? I'm not so sure on that...
Might be better to move the TC back a few inches.

G.

I jumped under there yesterday to peek at it. There's plenty of wiggle room for a longer tranny. Moving the TC is a viable option if there's not enough room. The only problem I saw was the PTO is pretty far off to the side from the tranny. I'm not sure an aftermarket double output PTO & drive shafts would clear either the engine or the TC

I shoved a chevy V8 & an auto tranny in an old FJ Cruiser. Now that's a shoe horn of a conversion. Trust me, that driveshaft to the TC in the A2 is plenty long to be chopped if needed. It even has U joints on it which gives more freedom to tweak engine/tranny position.

The TC swap sounds interesting. It could relocate the PTO to the TC if needed.